Treatment of symptomatic hyponatremia with hypertonic saline: a real-life observational study

Abstract

Objective: Treatment of symptomatic hyponatremia is not well established. European guidelines recommend bolus-wise administration of 150ml of 3% hypertonic saline. This recommendation is based, however, on low level of evidence. Design: Observational study Methods: Sixty-two consecutive hyponatremic patients admitted to the emergency department or intensive care unit of the University Hospital Wuerzburg were divided in subgroups according to treatment (150ml bolus of 3% hypertonic saline or conventional treatment), and symptom severity. Treatment target was defined as an increase in serum sodium by 5-10mEq/L within first 24h and maximum 8mEq/L during subsequent 24h. Results: 33/62 patients (53%) presented with moderate and 29/62 (47%) with severe symptoms. 36 were treated with hypertonic saline and 26 conventionally. In the hypertonic saline group serum sodium increased from 116±7 to 123±6 (24h) and 127±6mEq/L (48h) and from 121±6 to 126±5 and 129±4mEq/L in the conventional group, respectively. Overcorrection at 24h occurred more frequent in patients with severe than moderate symptoms (38% vs. 6%, p<0.05). Diuresis correlated positively with the degree of sodium overcorrection at 24h (r=0.6, p<0.01). Conventional therapies exposed patients to higher degrees of sodium fluctuations and an increased risk for insufficient sodium correction at 24h compared to hypertonic saline (RR 2.8, 95% CI 1.4-5.5). Conclusion: Sodium increase was more constant with hypertonic saline, but overcorrection rate was high, especially in severely symptomatic patients. Reducing bolus-volume and reevaluation before repeating bolus infusion might prevent overcorrection. Symptoms caused by exsiccosis can be misinterpreted as severely symptomatic hyponatremia and diuresis should be monitored.

Forgotten cause of severe hyponatremia

“…Proposed mechanism for the hyponatremia in hypothyroid patients is the elevation of antidiuretic hormone together with mild renal impairment [20][21][22][23]. Symptomatic hyponatremia should be urgently solved with intravenous 3% saline solution according to current guidelines, having in mind that too fast elevation of sodium can result in pontine myelinolysis [1,24,25,26]. Timely diagnosis of ShS is needed in order to initiate adequate hormonal supplementation, and the hydrocortisone and levothyroxine are of vital significance.…”

Edelman Revisited: Concepts, Achievements, and Challenges

“…Treating dysnatremia by infusing the same volume of saline to all patients will result in different changes in [Na] S in patients with different TBW values. Chifu and coinvestigators reported overcorrection of [Na] S in 21% of all hyponatremic patients and 47% of hyponatremic patients with severe symptoms who received the same load of hypertonic saline ( 93 ). It is probable that low TBW, along with ongoing losses of fluids during treatment, accounted for this overcorrection.…”

The management of acute and chronic hyponatraemia

“…Patients treated with bolus hypertonic saline, however, had less fluctuations in pNa and reached correction thresholds more often than those treated with ‘conventional’ treatments. 50 …”